Cleaning article and method of manufacture



y 1965 A. A. WINSTON 3,182,346

CLEANING ARTICLE AND METHOD OF MANUFACTURE Filed April 29, 1963 INVENTORADOLPH A. WINSTON United States Patent 3,182,346 CLEANH'JG ARTICLE ANDMETHOD OF MANUFACTURE Adolph A. Winston, Darien, Conn, assignor toGeneral Foods Corporation, White Plains, N.Y., a corporation of DelawareFiled Apr. 29, 1963, Ser. No. 276,585 7 Claims. (Cl. 15-209) Thisinvention relates to a new and improved scouring article and method ofmanufacturing the same. More particularly, the invention is concernedwith creation of a laminated structure of metal wool filaments on abacking sheet.

Steel wool has heretofore been sold in the form of balls, ribbons andlike bodies wherein the metal wool filaments are assembled into aunitary construction adapted to be gripped by the user in scouring pots,pans and similarly soiled utensils. Such metal wool bodies or pads arelikely to undergo splitting of the metal filaments giving rise tounpleasant slivers which are offensive to the hands of the user. The arthas long sought to provide a mass of metal wool filaments suitablymounted on a backing material such as paper or cloth so that the metalwool can be handled through the intermediation of a backing sheet andmanipulated without danger of filament slivers cutting the skin of theuser. The main limitation of prior art structures was that metal Woolfibers could not be faithfully mounted in any practical manufacturingoperation in such manner that they were stationed permanently anduniformly on the backing member throughout the anticipated period ofuse. Since metal wool filaments are preferably mounted on a backingmember in a corrugated pattern to provide greater scouring effect, nadirportions of the undulations proximate the backing member present anuneven surface to any adhesive employed to bond the individual metalfilaments to the backing. Accordingly there is a tendency for thecorrugated metal filaments to be unanchored as produce or unravel in useand thereby lose the desired corrugated pattern.

In accordance with the present invention a disposable cleansing andscouring article is provided by laminating corrugated metal filaments toa compressible spongiform ply. Such lamination is carried out by firstfeeding an endless ribbon of matted metal filaments into the pinchbetween a pair of corrugating rolls. The corrugated ribbon is thentrained into the nip between a pair of laminating rolls. A continuousstrip of deformable resilient spongiform material is trained around oneof the laminating rolls and brought into proximate relation to thecorrugated filaments at the nip between the laminating rolls. A heatactivatable resinous material, e.g. polyethylene, is deposited in theform of a vertically descending molten film of substantial thicknessbetween the juxtaposed strips of spongiform material and the corrugatedmetal wool filaments.

Due to the compressibility of the spongiform material and the plasticityof the molten resin, the concave undulating nadir portions of thecorrugations displace the resin into the surface of the spongiform stripwhile being surrounded by the resin as the juxtaposed plies pass throughthe nip between the laminating rolls. By virtue of the ability of themetal wool to dissipate the heat of the resin, the laminating film israpidly reduced in temperature to a point where it sets to permanentlyanchor the filaments and the film per se in place on the backing ply.While heat transfer from the resin is effected rapidly, setting of theresin occurs only after resin penetration at the surface of thespongiform sheet and around the nadirs in the corrugated metalfilaments.

In carrying out lamination, the extrusion orifice through which the hotmolten plastic material is caused to issue should be located proximatethe nip between the oppositely rotating laminating rolls whereby theplastic material falls in free-film form at a sufficiently elevatedtemperature so as not to undergo premature solidification, i.e., firmingto a point whereat the resin cannot orient itself to migrate around themetal filaments and enetrate the surface of the spongiform material. Themolten free film may be solidified after lamination by cooling one orboth of the two laminating rolls over which the spongiform sheet and themetal filaments pass so as to assure that the laminated structure willbe transferred unitarily without delamination to the succeeding stationsof the fabricating operation. These stations will involve impregnationof a soap foam or molten soap in the laminated structure, drying thesoap and then cutting the soap-impregnated product. For such subsequentoperations the free-film of thermoplastic resin, as in the case ofpolyethylene, should be substantially set shortly after lamination sothat any extraneous liquids, such as the fats contained in liquid ormolten soap, do not detract from the extent of filament anchoring.

Due to compressibility of the spongiform backing ply, the metal woolcorrugations are not flattened incident to application of the laminatingpressure called for in bringing the metal filaments into intimatecontact with the spongiform material and the molten thermoplasticlaminant. To afford retention of the corrugated pattern, therefore, thebacking sheet should be of a highly compressible character such as isoffered by urethane plastic foam and like resilient spongiformcompositions to be hereinafter described.

When viewed in cross section, the composite structure will be seen tohave corrugated depressions therein complementary to the nadir portionsof the corrugated metal wool filaments, the intermediate laminating filmbeing in the form of a continuous corrugated membrane. It is a featureof the present structure that the crests at the working surface of themetal wool filaments are substantially free from contact with thelaminant film; while the nadir portions of the filaments are maintainedin an immobile orientated pattern by being anchored at the concaveportions of the corrugations only. The anchored metal filaments offerthe maximum scouring effect, through the cutting action of the flexiblefilaments, as they orient themselves freely when contacting soil on theworking surface of a pot, pan or other utensil requiring cleansing,

The invention will now be more fully understood by reference to theaccompanying drawings showing a preferred method for manufacturing thearticle of the present invention and also describing the article.

In the drawings:

FIGURE 1 is a schematic side elevation of equipment for laminating themetal wool filaments to a spongiform backing sheet; FIGURE 2 is aperspective view of a laminated corrugated scouring article produced bythe apparatus depicted in FIGURE 1; and FIGURE 3 is a side elevationtaken partly in elevation and partly in section along line 33 in FEGURE2, a part of the side section in FIG- URE 3 being magnified to betterillustrate the features of the present invention.

Referring now to FIGURE 1, the apparatus shown therein consists of anunwind roll it? mounted for rotation on journals 12 housed on stand 14.A roll of highly compressible resilient urethane foam 16 ribbon istrained around guide rolls 18, 20, 22, and 24 adapted to lead the foamribbon 16 over metal laminating roll 26.

A ribbon of metal wool shown generally at 28 is introduced to the nipbetween a pair of oppositely rotating corrugating rolls 30, 32, tocreate corrugations in the metal wool ribbon 28, the corrugated metalfilaments and the undulations therein being more particularly describedhereinafter with respect to FIGURES 2 and 3: die 34 mounted on thedischarge end of an extruder (not shown) is mounted superjacent the nipbetween corrugating roll 30 and laminating roll 26 whereby apolyethylene filrn36 is fed to the laminating nip in a manner to be moreparticularly described hereinafter.

The corrugated metal wool filaments are thus laminated to the foamribbon 16 through the intermediation of molten resin film 36 and areconducted away from the laminating station of take-off rolls 38, 40,substantial solidification of the laminant being achieved in thevicinity of the laminating station, which solidification may be assuredby cooling laminating roll 26 internally.

The laminated corrugated metal wool filaments and foam ribbon compositeshown generally at position 42 is conducted beneath a pair of soap rolls44, 46 operated in the directions shown by the arrows to deposit fromsoap nozzle 49 a uniform ribbon of hot molten soap onto the corrugatedside of composite 4-2, the soaped laminated structure being conductedunder the control or" guide roll' 48 into a conventional vertical driergenerally shown at 50 wherein the moisture is removed from the soap bytraining the composite over a plurality of pulleys (not shown) under theinfluence of circulating hot air.

The dried composite issuing at 52 from drying chamber 50 is thenconducted by guide rolls 54, 56 into flying cutter 58 wherein the ribbonis divided into pads of the dimensions shown in FEGURE 2.

Referring now to FIGURE 2, the pad thus produced will be seen to consistof a corrugated metal wool ply 100 laminated through the intermediationof a solidified thermoplastic anchoring ply 102 to a compressiblespongiform ply 104. As will be seen from FIGURE 3, and more particularlythe magnified section thereof, the undulations of the metal woolfilaments are alternately anchored in place by laminant 102 as at 1'06and freely displaceable and unanchored as at E08 providing a void spacebetween the crests of the laminant at 110 and the intermediatethermoplastic ply 102. As seen in FIGURE 3, the concave undulations ofthe metal Wool filaments are immersed in the thermoplastic substantiallyno that the material of ply 102 surrounds a substantial portion of thenadirs of the filaments as at 112, thereby assuring permanent anchoringof the filaments to the laminant.

As will also be seen inFIGURE 3, the laminant per se assumes a wavelikecross-section by reason of the substantially complementary pattern ofthe laminant to the various nadirs of the individual metal woolcorrugations. This corrugated laminant ply-102 will also be seen to besubstantially anchored to the compressible plastic foam ply 104, whichadhesion is in part attributed to migration of the molten laminant intothe voids or pockets at the surface of the foam ribbon during thelamination process. To achieve this preferred anchoring of the laminantresin, it is maintained sumciently high in temperature above itssolidification point as it is extruded in'free film 36 that asubstantial migration of the polymer can occur. However, the temperatureis preferably not sufiiciently elevated to a point whereat it cannot berapidly solidified after lamination of the corrugated ply to thecompressible plastic foam.

In achieving the desiredlaminated structure, the amplitude of thecorrugations, the thickness of the foam ribbon, the thickness of film 36and the ultimate ply thereof 102, the compressibility of the corrugatedmetal wool ribbon and the foam ribbon, and the speed-of lami-.

nation are all interrelated factors which should be taken into accountin adjusting nip clearance to achieve the desired laminated structure. Anarrow nip clearance will .imbed the metal filaments too deeply into thelaminant and the resilient backing whereby an insuflicient amount ofcorrugated steel or other metal wool is available for scouring. On theother hand, a nip clearance that is too wide will not result insufiicient immersion of filament nadir portions to firmly anchor themetal wool to the backing. The nip clearanceshould be sufiicient topromote substantial immersion of the nadir portions of the corrugationsin the laminant and permit anchoring of individual metal filaments whileleaving substantial freedom to the crest portions thereof. In all suchlaminations this is achieved by bringing the corrugated metal woolribbon into compressing relation to the foam ribbon under conditionswhereby the latter will yield undervthe laminating pressure transmittedthrough the molten adhesive and result in a sinusoidal pattern in thesolidified laminating ply. Hence the foam ribbon should be sufiicientlycompressible to allow distortion sufficient to receive the nadirportions of the metal wool corrugations during the laminating operation.

The metalwool material may be aluminum, steel, or any other metallicfiber having a cutting edge produced therein incident to filamentproductions, although the invention is not restricted to use of metalfilaments derived by any particular method.

The preferred foam ribbon has become possibly known as urethane orpolyurethane foam and is generically chemically identifiable as a foamedisocyanate resin. The preparation of polyurethane foams from freeisocyanate radical-containing polyurethane products results from thereaction between (1) an alkyd or other. active hydrogencontainingorganic polymeric material and (2) organic compounds containing, as thesole reacting groups; a plurality of isocyanate groups is described inGerman Plastics Practice, by De Bell et al., 1946, pp. 316 and 463- 465.Disclosures of reactants and methods which may be employed to producepolyurethane foams of use in preparing the foam ribbon are United StatesPatents 2,282,-

827 (Rothrock), 2,284,637 (Catlin), 2,284,896 (Hanford et al.),2,292,433 (Hanford), 2,333,639 (Christ et al.), 2,358,475 (Pratt etal.), and 2,374,163 (Rothrock); and United States patent applicationsSerial Nos. 340,168 (Detrick et al.), filed March 13, 1953, now PatentNo. 2,787,601; 369,240 (Barthel), filed July 20, 1953, now Patent No.2,788,335; 381,745(Mitchell), filed September 21, 1953, now Patent No.2,850,464; 383,370 (Barthel), filed September 30, 1953, now Patent No.2,833,730; 395,843 '(Roussel), filed December 2, 1953, now Patent No.2,842,506; and 405,036 (Mitchell), filed January 19, 1954, now PatentNo. 2,814,600.

However other foamableresinous thermoplastic compositions capable ofoffering the desired compressibility and foam structure may be employedsuch as rubber sponge, cellulose sponge and like compositions 'wellknown in the art. Although the invention preferablyemploys compressiblefoamed resins whose structure in the superficially dry state per se issuch that the material is sufiiciently deformable to receive the nadirportions of the metal wool corrugations, it is also within the spirit ofthe present invention'that any compressible spongiform plastic materialwhich may be relatively uncompressible in the dry state and renderedtemporarily compressible in the wet state (such as axwet cellulosesponge) may be used in such wet state as the ribbon 16 is fed to the nipbetween the laminating rolls; the wet laminated ribbon may be thereafterdried incident to removing moisture from the soap applied'to thecomposite 42.

The composition ofthe'laminant ply should be one like low densitypolyethylenethat is readily film forming and may be converted into amolten sheet susceptible to rapid solidification after the applicationof laminating pressure to the corrugated ply and the backing ply.Typically any one of the known polymerized olefin resins such aspolyethylene, polpropylene and polystyrene, etc. may be used with orwithout a tackifying or plastisol'additive, all of which is well knownto those skilled'in the art. The adhesive composition shouldbepreferably thermoplastic and be of'sufiicientviscosity to migrate aroundthe monofilaments and 'occupy the pores'a't the'surface of theundulating indented compressed portions of the backing ply.

The laminant should also be capable when set of retaining a shapecomplementary to that produced incident to distortion under thelaminating pressure applied thereto.

The advantages of the present invention are that the aforesaid compositestructure is produced with corrugations of either a sinusoidal or anyother undulating pattern capable of providing a good scouring efiectwithout sacrificing good bonding of the nadir portions of thecorrugations to the backing material. By reason of the spongiformbacking material called for in producing this laminated structure, theindividual voids and vesicles therein provide improved soap retentionfor the life of the pad, and hence improve the overall scouringefiectiveness of the article throughout its anticipated period of use.The backing acts as a reservoir feeding soap to the working surface ofthe metal wool facing ply 100 at a rate which makes its scouring andcleansing activity more effective, particularly in view of the mobilityof the crests of the well-anchored filaments. By virtue of theconsistency aiforded in bonding the metal wool corrugations to thebacking and the simplicity of the laminating process, this procedurelends itself to acontinuous, low-cost, troublefree manufacturingoperation assuring a uniform laminated structure with a minimum of plantsupervision.

What is claimed is:

1. A composite scouring article comprising a corrugated metal wool ply;a compressible spongiforrn backing ply; and an intermediate laminatingply of thermoplastic resin adhesive; the laminating ply havingundulations therein complementary to the nadir portions of thecorrugations in the metal Wool ply and anchoring individual filamentsthereof in the composition of the laminating ply at the nadir portionsthereof; the backing ply having undulating indented compressed porousportions therein complementary to those of the laminating ply, thecomposition of the laminating ply being adhered to the compressedundulating portions of the backing ply and ccupying the pores at thesurface thereof.

2. A scouring article according to claim 1 wherein the crest portions ofthe metal wool filaments are free of contact with the composition of thelaminating ply so as to be mobile at the working surface of the scouringarticle.

3. Process for laminating a compressible spongiform backing ply to ametal wool ply which comprises pressing said metal wool ply into acorrugated form having alternate nadir and crest portions, introducingsaid backing ply to the corrugated metal wool ply through theintermediation of a molten thermoplastic laminating resin depositedbetween juxtaposed surface of the backing ply and the metal wool ply,applying on the nadir portions of said corrugated metal wool plylaminating pressure to the juxtaposed plies sufficient to cause thenadir portions of the corrugated ply to transmit laminating pressurethrough the intermediate molten laminant and produce complementarydepressions in the backing ply whereby the laminant ply assumes apattern substantially complementary to the pattern of the nadir portionsof the corrugated metal wool ply and the molten laminant is caused toanchor the filaments in place.

4. The process of claim 3 wherein said backing ply and said corrugatedmetal wool ply are juxtaposed continuously in the form of ribbons fedrespectively to the nip between 21 pair of laminating rolls.

5. The process of claim 4 wherein said molten thermoplastic resin isextruded as an unsupported free film which contacts the juxtoposed pliesjust prior to the application of laminating pressure thereto.

6. A scouring article according to claim 1 wherein the undulations inthe backing ply are equal in pitch and unequal in amplitude to theundulations of said corrugated metal wool ply.

7. A scouring article according to claim 6 wherein the undulations inthe backing ply are of lesser amplitude than that of the undulations ofsaid corrugated metal wool ply.

References Cited by the Examiner UNITED STATES PATENTS Re. 25,200 7/62Robinson et al l56-244 2,493,968 1/50 Hepner 15-209 X 2,897,109 7/59Voigtman 156-244 X 3,074,099 1/63 Cameron 15-506 3,080,688 3/63 Politzer15-297 X CHARLES A. WILLMUTH, Primary Examiner.

1. A COMPOSITE SCOURING ARTICLE COMPRISING A CORRUGATED METAL WOOL PLY;A COMPRESSIBLE SPONGIFORM BACKING PLY; AND AN INTERMEDIATE LAMINATINGPLY OF THERMOPLASTIC RESIN ADHESIVE; THE LAMINATING PLY HAVINGUNDULATIONS THEREIN COMPLEMENTARY TO THE NADIR PORTIONS OF THECORRUGATIONS IN THE METAL WOOL PLY AND ANCHORING INDIVIDUAL FILAMENTSTHEREOF IN THE COMPOSITION OF THE LAMINATING PLY AT THE NADIR PORTIONSTHEREOF; THE BACKING PLY HAVING UNDULATING INDENTED COMPRESSED POROUSPORTIONS THEREIN COMPLEMENTARY TO THOSE OF THE LAMINATING PLY, THECOMPOSITION OF THE LAMINATING PLY BEING ADHERED TO THE COMPRESSEDUNDULATING PORTIONS OF THE BACKING PLY AND OCCUPYING THE PORES AT THESURFACE THEREOF.
 3. PROCESS FOR LAMINATING A COMPRESSIBLE SPONGIFORMBACKING PLY TO A METAL WOOL PLY WHICH COMPRISES PRESSING SAID METAL WOOLPLY INTO A CORRUGATED FORM HAVING ALTERNATE NADIR AND CREST PORTIONS,INTRODUCING SAID BACKING PLY TO THE CORRUGATED METAL WOOL PLY THROUGHTHE INTERMEDIATION OF A MOLTEN THERMOPLATSTIC LAMINATING RESIN DEPOSITEDBETWEEN JUXTAPOSED SURFACE OF THE BACKING PLY AND THE METAL WOOL PLY,APPLYING ON THE NADIR PORTIONS OF SAID CORRUGATED METAL WOOL PLYLAMINATING PRESSURE TO THE JUXAPOSED PLIES SUFFICIENT TO CAUSE THE NADIRPORTIONS OF THE CORRUGATED PLY TO TRANSMIT LAMINATING PRESSURE THROUGHTHE INTERMEDIATE MOLTEN LAMINANT AND PRODUCE COMPLEMENTARY DEPRESSIONSIN THE BACKING PLY WHEREBY THE LAMINANT PLY ASSUMES A PATTERNSUBSTANTIALLY COMPLEMENTARY TO THE PATTERN OF THE NADIR PORTIONS OF THECORRUGATED METAL WOOL PLY AND THE MOLTEN LAMINANT IS CAUSED TO ANCHORTHE FILAMENTS IN PLACE.